build: remove unused gulp test watch code (#18077)

We can remove the unused code for `gulp test` and `gulp test:static`.
The equivalent actions can be performed with Bazel and with the upcoming
script that simplifies the testing workflow, there is no need for
keeping this code in the codebase. All the concerns that have been
mentioned in the old PR (#16904) have been resolved.

tools/gulp/packages.ts

@@ -8,14 +8,3 @@ export const cdkExperimentalPackage = new BuildPackage('cdk-experimental', [cdkP
 export const materialExperimentalPackage = new BuildPackage('material-experimental',
     [cdkPackage, cdkExperimentalPackage, materialPackage]);
 export const momentAdapterPackage = new BuildPackage('material-moment-adapter', [materialPackage]);
-
-/** List of all build packages defined for this project. */
-export const allBuildPackages = [
-  cdkPackage,
-  materialPackage,
-  youTubePlayerPackage,
-  cdkExperimentalPackage,
-  materialExperimentalPackage,
-  momentAdapterPackage,
-  googleMapsPackage,
-];

tools/gulp/tasks/unit-test.ts

@@ -1,17 +1,7 @@
 import {join} from 'path';
-import {task, watch} from 'gulp';
+import {task} from 'gulp';
 import {buildConfig, sequenceTask} from '../../package-tools';
 
-// There are no type definitions available for these imports.
-const runSequence = require('run-sequence');
-
-// Default Karma options.
-const defaultOptions = {
-  configFile: join(buildConfig.projectDir, 'test/karma.conf.js'),
-  autoWatch: false,
-  singleRun: false
-};
-
 /** Builds everything that is necessary for karma. */
 task(':test:build', sequenceTask(
   'clean',
@@ -32,60 +22,13 @@ task('test:single-run', [':test:build'], (done: () => void) => {
   // Load karma not outside. Karma pollutes Promise with a different implementation.
   const karma = require('karma');
 
-  new karma.Server({...defaultOptions, singleRun: true}, (exitCode: number) => {
+  new karma.Server({
+    configFile: join(buildConfig.projectDir, 'test/karma.conf.js'),
+    autoWatch: false,
+    singleRun: true
+  }, (exitCode: number) => {
     // Immediately exit the process if Karma reported errors, because due to
     // potential still running tunnel-browsers gulp won't exit properly.
     exitCode === 0 ? done() : process.exit(exitCode);
   }).start();
 });
-
-/**
- * [Watch task] Runs the unit tests, rebuilding and re-testing when sources change.
- * Does not inline resources.
- *
- * This task should be used when running unit tests locally.
- */
-task('test', [':test:build'], karmaWatchTask());
-
-/**
- * Runs a Karma server which will run the unit tests against any browser that connects to it.
- * This is identical to `gulp test`, however it won't launch and manage Chrome automatically,
- * which makes it convenient debugging unit tests against multiple different browsers.
- */
-task('test:static', [':test:build'], karmaWatchTask({browsers: []}));
-
-/**
- * Returns a Gulp task that spawns a Karma server and reloads whenever the files change.
- * Note that this doesn't use Karma's built-in file watching. Due to the way our build
- * process is set up, Karma ends up firing its change detection for every file that is
- * written to disk, which causes it to run tests multiple time and makes it hard to follow
- * the console output. This approach runs the Karma server and then depends on the Gulp API
- * to tell Karma when to run the tests.
- * @param options Karma options to use on top of the defaults.
- */
-function karmaWatchTask(options?: any) {
-  return () => {
-    const patternRoot = join(buildConfig.packagesDir, '**/*');
-    // Note: Karma shouldn't be required from the outside, because it
-    // pollutes the global Promise with a custom implementation.
-    const karma = require('karma');
-
-    // Configure the Karma server and override the autoWatch and singleRun just in case.
-    const server = new karma.Server({...defaultOptions, ...options});
-
-    // Refreshes Karma's file list and schedules a test run.
-    // Tests will only run if TypeScript compilation was successful.
-    const runTests = (error?: Error) => {
-      if (!error) {
-        server.refreshFiles().then(() => server._injector.get('executor').schedule());
-      }
-    };
-
-    // Boot up the test server and run the tests whenever a new browser connects.
-    server.start();
-    server.on('browser_register', () => runTests());
-
-    // Whenever a file change has been recognized, rebuild and re-run the tests.
-    watch(patternRoot + '.+(ts|scss|html)', () => runSequence(':test:build', runTests));
-  };
-}